Zuo Z, et al. - In this retrospective study including 243 consecutive patients, 112 (46.1%) of whom were male and with a median age of 58 years (IQR 49–68), the prognostic value of copeptin in aneurysmal subarachnoid hemorrhage (aSAH) was assessed. Enzyme-linked immunosorbent assay was used to determine plasma copeptin levels at admission. Mortality and poor functional outcome (Glasgow Outcome Scale score of 1–3) were assessed after 3 months. Increases in the adjusted risk of poor outcomes and mortality by 6% and 9%, respectively, would be seen in relation to each 1 pmol/l increase of plasma concentration of copeptin. Overall, at its onset in aSAH patients, short-term prognosis could be reliably predicted by copeptin levels. Significantly higher copeptin levels on admission were seen in patients with a poor outcome and nonsurvivors.